#include <iostream>
#include <string>
using namespace std;
string Sul(string a, int m, int n) {
	long long sum = 0;
	string res = "";
	for (int i = 0; i < a.size(); i++) {
		if (a[i] >= '0' && a[i] <= '9')
			sum = sum*m+(a[i] - '0');
		else
			sum = sum*m+(a[i] - 'A' + 10);
	}
	if (sum == 0)
		return "0";
	while (sum > 0) {
		if (sum % n < 10)
			res = char(sum % n + '0') + res;
		else
			res = char(sum % n - 10 + 'a') + res;
		sum /= n;
	}
	return res;
}
int main() {
	int m, n;
	cin >> m >> n;
	string s;
	cin >> s;
	cout << Sul(s, m, n) << endl;
	return 0;
}

注：m进制转10进制时一定要从前往后加和，和每次乘以进制数。